CONSOLIDATED STATEMENTS OF CASH FLOWS (Parenthetical) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Dec. 31, 2020	Dec. 31, 2019
Statement of Cash Flows [Abstract]
Cash acquired from acquisition	$ 52.2	$ 13.4
Restricted cash balance	$ 96.7	$ 82.9	$ 78.4	$ 56.3